Focal Atrial Tachycardia Originating From the Right Atrial Appendage Masquerading as Inappropriate Sinus Tachycardia.

Focal atrial tachycardia arising from the right atrial appendage (RAAT) may be misdiagnosed as sinus tachycardia. The electrocardiogram from this case demonstrates a negative notched P-wave in leads V and V during RAAT compared with a beat of sinus rhythm. RAAT was confirmed and eliminated with mapping and ablation.

Hypertrabeculation; a phenotype with Heterogeneous etiology.

Left ventricular hypertrabeculation (LVHT) is a phenotype with multiple etiologies and variable clinical presentation and significance. It is characterized by a 2-layer myocardium with an enlarged trabecular layer and a thinner compacted layer. The prevalence has been increasing due to advances in cardiac imaging.